In its quality of attention and faith in the salvific power of the right words in the right order, the essay resembles nothing so much as a secular prayer. That, at least, was the original point. The essay has proved wayward, which has been the great secret to its longevity.

Invented in France by Michel de Montaigne, the 16th century’s great oversharer; perfected in England by Samuel Johnson and William Hazlitt; the essay found America very agreeable: “The United States itself — and even its name, according to some sources — is partly the outcome of the essayistic brilliance of the radical English artisan Thomas Paine,” Christopher Hitchens, one of its finest modern practitioners, wrote. Its health, however, has never been guaranteed.

Virginia Woolf had to reassure the public in 1922: “Oh, yes dear reader: the essay is alive. There is no reason to despair,” even as journalists crowed over the death of “that lavender-scented little old lady of literature.” “Everybody is forever saying that the essay is dead,” John Leonard observed in 1982. “This is always said in essays.”

The essay doesn’t die. It’s too protean. It only grows more indispensable as it learns to mimic, then amplify, our senses. The essay is a way of seeing through language, and in language. It grasps and sifts — recall its cognate “assay,” the distinguishing of base metals and gold. And if we like our art forms promiscuous and free, it obliges. Joan Didion turned it on to doubt in the 1970s, admitting in her collection “The White Album” that writing about her experience “has not yet helped me see what it means,” and an already supple form became even more elastic. The “lavender-scented little old lady of literature” has loosened her stays.

Only a certain breed of literary essay retains some starch. The book review, for example, with its formality and abstractions, its ego and aggression tamped down. Not for it the ecstasy of doubt; it trudges from certainty to certainty.

But in such strictures self announces itself in style. Think of Virginia Woolf’s unsigned reviews in The Times Literary Supplement. The “anonymity was ideal,” James Wood explains. “Surely Woolf knew that her prose had to sign itself. So her essays, both in texture and in content, were self-advertisements.” This is true too of Wood himself, a staff writer at The New Yorker, with his clearly delineated — and undeviating — theory of how fiction works and what it must do. Raised in the evangelical tradition, he possesses a faith in fiction that is absolutist, and teleological; “It was not just the ascent of science but perhaps the ascent of the novel that helped to kill off Jesus’s divinity,” he has written. He reads messianically, with a hunger for fiction to answer the questions religion once did.

Wood’s new book, THE FUN STUFF: And Other Essays (Farrar, Straus & Giroux, $27), possesses many of the pleasures of his previous collections “The Broken Estate” (1999) and “The Irresponsible Self” (2004): the same tight weave, the laconic humor, the genius for metaphor (Flaubert, “the agonist of style, assassinated repetitions like insects.”). He keeps bringing us back to Chekhov, Tolstoy, Flaubert — about the old masters, Wood is never wrong — founts of psychological insight. No one is better at alerting us to influences with such gossipy familiarity: just as Orwell “almost certainly” got his “eye for didactic detail from Tolstoy,” Wood tells us, Ian McEwan in turn “learned quite a lot about narrative stealth and the control of disgust from Orwell.” And no critic gets closer to the text. Wood writes that Edmund Wilson “seems to rear panoptically above his subjects, like a statue overseeing a city square.” Wilson looms over the work; Wood seems to speak from within it. On Norman Rush’s “Mating”: “The novel has the air at times of a once fatter man whose thinner frame is now making his skin sag a bit: there are abrupt transitions and sudden deposits of information.” He is critic as coroner, reporting on the source of life or root of disease. He can be surprisingly squeamish, though; he shudders at how Wilson would “happily gut a living novelistic organism with the blunt blade of précis.”

But “The Fun Stuff” is notable for what it does not include. There is no introduction. Wood establishes no unifying thesis or theme. For a writer so fond of system building, the silence is puzzling. Our most consistent critic is changing. In his tightly pleached arguments, he’s making room for the reader, and a fresh inquiry. He’s moving past fiction’s possibilities to linger on its limitations, on the books that explore what happens when language becomes insufficient and storytelling breaks down. How the starved sentences of Lydia Davis’s later stories flirt with muteness and leak grief. How “Leaving the Atocha Station,” an American-abroad novel by the poet Ben Lerner, reaches “for what cannot be disclosed or confessed in narrative.” How “The Road,” Cormac McCarthy’s apocalyptic Grand Guignol, evades its own crucial question: “As long as language can be used to recount the worst, then the worst has not arrived. . . . When does narrative, language end?”

We see too his attraction to narratives of exile, unreliable memory and uneasy citizenship, to people “mugged by history,” as he describes the Bosnian-born writer, Aleksandar Hemon. Wood loves the forked consciousness, the immigrant’s delight in refreshing the English language’s possibilities — Nabokov and Hemon’s taste for the oddly pronged adjective or the “enraptured and faintly alienated” perspective of Joseph O’Neill’s Dutch narrator of “Netherland,” who sees New York as a “garbage of light.” “The Fun Stuff” features exhilarating readings of Hemon and O’Neill, W. G. Sebald, Ismail Kadare and V. S. Naipaul. Few can parse with as much economy and sophistication how estrangement corrodes and strengthens character, sharpens and clouds perception. He’s interested in what we do with our wounds — how, for the outsider and immigrant, knowledge can be protection; mastery, revenge. “I have got to show these people that I can beat them at their own language,” a young Naipaul wrote home to his family in Trinidad during his lonely years studying at Oxford. Seeded in Wood’s essay on George Orwell is his connection to such stories: he was a scholarship boy at Orwell’s own school, Eton, “alternately grateful for its every expensive blessing and yearning to blow it up.” He understands the wages of “productive shame.”

In the final essay, “Packing My Father-in-Law’s Library,” a self-portrait at slant angle, Wood tries to find a home for a very large and very eccentric book collection. It’s a play on Walter Benjamin’s classic essay “Unpacking My Library,” but where Benjamin sweatily fondles his fetishes, Wood wrings his hands. He laments how meaningful a library is to its collector, and how worthless it is to anyone else. He fantasizes about someone mysteriously carting off all his own books. How free he’d feel. It’s an elegant terminus, a vanishing point where all the lines intersect. At every moment the words are running out, the time is running out. The books remain — but without someone to release their meaning, they are so much dross.

Wood compels, but he won’t sway the reader. He’s too idiosyncratic and forceful in his method. But hold tight to your convictions while reading Daniel Mendelsohn lest you absorb his own. You’ll want to. They’re always more deeply considered, generous in spirit, fresher and funnier than yours. A contributor to The New Yorker and The New York Review of Books, Mendelsohn just might be our most irresistible literary critic, and his new collection, WAITING FOR THE BARBARIANS: Essays From the Classics to Pop Culture (New York Review Books, $24.95), features readings of high and low culture, from Anne Carson to “Avatar,” with an eye to the endurance of classical themes.

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His approach is systematic and pedagogical. He begins his books by announcing their major themes and explaining their structures. In “How Beautiful It Is and How Easily It Can Be Broken,” he even offered up his qualifications. This new collection is as lucid and more assured; instead of dithering in the foyer, hat in hand, presenting his C.V., Mendelsohn strides in with a majestic “Don’t worry.”

These essays take on “the reality problem,” he tells us, the “extraordinary blurring between reality and artifice” made possible by new genres and new technologies. And Mendelsohn is especially fond of analysis that itself collapses this distance, that traces the success or failure of a work to the character of its creator. Thus the Broadway musical “Spider Man: Turn Off the Dark” didn’t flop merely because of lousy songs, legal troubles and ghastly accidents but because the director Julie Taymor, “like a character in some Attic play,” was “led by a single-minded passion to betray her truest self and abandon her greatest virtues.” The artist with a taste for spare, spiritually inflected spectacles, who had sworn she had no intention of making, say, “Batman: The Musical,” had gone and done just that.

Susan Sontag suffers from the same hamartia, according to Mendelsohn, who is endlessly fascinated by how the lack of self-knowledge makes self-betrayal inevitable. She belonged to the 19th century, he writes, which explains the “aspirations that were at odds with her temperament and her talent.” She insisted she be known as a storyteller, when the very qualities that made her so exciting a critic — the self-consciousness and “inability to resist any opportunity to interpret” — made her a clunky and banal novelist. The self, to Mendelsohn’s trained classicist’s eye, is gloriously rived. Forget reconciling its contradictions — the self can scarcely see them.

Cheerfully pessimistic though he may be, he is never an alarmist (remember that “Don’t worry”). He practices a civilized, soothing form of criticism, his intellect an alembic that purifies, restores calm and historical context. “What others might see as declines and falls look, when seen from the bird’s-eye vantage point of history, more like shifts, adaptations, reorganizations,” he writes. This constitutional temperance gives his prose its legato rhythms, the languorous judgments; he might be a cat toying with his prey.

And much of the fun of reading Mendelsohn is his sense of play, his irreverence and unpredictability, his frank emotional responses — he gasps in amazement while watching “Avatar,” he bursts into tears during Philip Glass’s opera “Satyagraha.” He forces the form in directions Francis Bacon never imagined. Which isn’t to say he can’t be brutal. He dispatches Jonathan Franzen so efficiently you can smell the cordite. Discussing “The Discomfort Zone,” a “thin and insubstantial” essay collection, as well as the novelist’s peevish response to being selected for Oprah’s Book Club, Mendelsohn attributes Franzen’s habit of “snide superiority” to a case of arrested adolescence so severe it amounts to a “political and aesthetic autism.”

“Character will out” is the refrain of this book, but as Mendelsohn points out in his essay on “Mad Men,” strengths and flaws frequently flow from the same root. Just because the structure cannot hold doesn’t mean we cannot enjoy the view. As a culture, we’re famously fond of ruins.

Since her first book, “The Morning After: Sex, Fear and Feminism,” was published in 1993, Katie Roiphe has been the professional gadfly of the women’s movement, checking what she perceives to be its excesses. She’s inveighed against rules forbidding sexual harassment, arguing that such strictures deny workers a “vivid office culture.” She’s found feminists guilty of inflicting upon readers a generation of flaccid male novelists too cowed and politically correct to live up to their rowdy predecessors. Her preoccupation with defending male sexuality recalls Rebecca West, whom Christopher Hitchens memorably described as “a superbly intelligent woman, whose feminism was above all concerned with the respect for, and the preservation of, true masculinity.”

It’s a pity that the bombast of her writing on gender politics draws attention away from her writing on books. The 10 literary essays at the heart of IN PRAISE OF MESSY LIVES: Essays (Dial Press, $25) are wicked and endearing; the language is conversational and burnished to a hard shine. It’s impossible to read journalism the same way after reading Roiphe on how Joan Didion’s stylistic tics — her ironic use of quotation marks, her attention to news as narrative — have become clichés of the genre.

Untethered from a text, Roiphe is less sure-footed. As Daniel Mendelsohn might point out, the traits that make her a lively critic — her irascibility and unsparing eye, her predilection to pronounce rather than persuade — doom her as a personal essayist. Her pieces on her circle’s dreary obsession with health and domesticity devolve, turn personal and very sour. Paranoia and a lack of proportion bloom abundantly throughout these sections. She berates friends who inquired how she was doing after her divorce, insisting they were “invested in the idea that I am suffering some form of collapse.” Thinking a colleague has implied that she’s “getting away with something” by being a single mother, Roiphe wraps herself in righteousness and a paraphrase of James Baldwin: “He can face in your life only what he can face in his.” The actual quotation in its entirety reads: “The really ghastly thing about trying to convey to a white man the reality of the Negro experience has nothing whatever to do with the fact of color, but has to do with this man’s relationship to his own life. He will face in your life only what he is willing to face in his.” This clumsy appropriation of a specific power relationship and its application to the sex wars in the N.Y.U. faculty lounge is just one example of how solipsistic these sections can get, and why this book, fascinating and joyfully acerbic though it may be, discomfits, even repels. If fiction casts a spell, essays exert a complicity, one that the writer must protect. The instant the reader begins to add up inconsistencies, she’s started to turn against you.

Personality is the essayist’s “most dangerous and delicate tool,” Virginia Woolf wrote. It’s also the most tempting. We see its risks with Roiphe and its rewards in the year’s most disheveling innovations: “My Poets,” by Maureen N. McLane, and “Madness, Rack and Honey,” by Mary Ruefle. Both books toggle between cool close readings and feverish interpretations, even deliberate distortions. Their criticism is moody and humid, kindled by lust and longing but never less than rigorous. This very essay, with its impersonality and tweediness, its claims at authority, seems dated in comparison, vulnerable. How much longer can it flourish when the fragment is more seductive than the argument, and personality is easier to convey than style? Will writers care to hide in public like this for much longer? Don’t worry. The essay will surprise and survive you yet.

Parul Sehgal is an editor at the Book Review.

A version of this article appears in print on December 30, 2012, on Page BR12 of the Sunday Book Review with the headline: The Wayward Essay. Order Reprints|Today's Paper|Subscribe